The company's stock closed Wednesday at $70.99, up $5.28 per share, or 8.04 percent. The stock price increase followed Tuesday's report that Yum's net income for the third quarter, ended Sept. 8, rose to $471 million, or $1 per share, diluted. That was up from $383 million, or 80 cents per share, diluted, a year earlier.

It’s the highest Yum stock has reached since May.

Yum benefiting from Taco Bell’s performance

In the United States, Yum (NASDAQ: YUM) continues to benefit from Taco Bell’s strong performance. Taco Bell had 7 percent same-store sales growth in the United States during the third quarter after launching its new Doritos Locos Tacos in March. The restaurant has sold more than 200 million of the tacos since the launch.

Officials said Wednesday on the company's conference call that they expect to roll out more varieties of the popular taco next year.

The company also introduced its Cantina Bell menu during the third quarter, which focuses on fresh, high-quality ingredients. The menu was developed by chef Lorena Garcia.

The Wall Street Journal on Wednesday afternoon quoted David Einhorn, president of Greenlight Capital, as saying Taco Bell is a real threat to Chipotle Mexican Grill Inc., in part because of the Cantina Bell menu.

Chipotle (NYSE: CMG) will release its third quarter earnings report on Oct. 18.

Chipotle missed its revenue projections by $16 million in the second quarter, sending its stock down as much as 21 percent on July 20 after the company warned extreme weather might increase food costs this year and next.

Stocks of other restaurant companies, including Yum, Texas Roadhouse Inc. (NASDAQ: TXRH) and Louisville-based Papa John’s International Inc. (NASDAQ: PZZA), were down as much as 3 percent following Chipotle’s earnings report.

When questioned by analysts Wednesday, Yum officials were hesitant to address the fears of higher commodity prices, but company chairman and CEO David Novak said the prices are “a significant issue.”

He said the company would provide more information at its investor conference in December.

“We have seen commodity peaks like this and have dealt with them,” Novak said. “We dealt with them through a combination of productivity measures, and we don’t expect that 2013 is going to be any different in that regard.”